The goal of this effort is to develop long, flexible neural probes with multiple sites (~100) for deep brain recording. If successful, this effort will have a profound and broad effect on neuroscience and the treatment of neural disorders since multi-channel (>4) deep neural implants do not currently exist. Planar integrated circuit technology will be adapted to pattern wires on the surface of cylindrically symmetric fibers for neural electrodes. These electrodes are intrinsically 3-dimensional and flexible with many recording/stimulating sites distributed along and around the fiber enabling a detailed understanding of neural pathologies and precise treatments. In phase I, a neural probe will be prototyped and used to record mammalian neural signals thereby demonstrating feasibility. The incorporation of integrated circuit microfabrication techniques will dramatically increase the number of recording/stimulation sites, improve reliability and reduce manufacturing costs for commercially available deep brain neural electrodes. This research and development effort is appropriate for NIMH topic 1B2 (Neurophysiology). PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE